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DIVISION OF RECLAMATION, MINING AND SAFETY <br />Department of Natural Resources <br />1313 Sherman St., Room 215 <br />Denver, Colorado 80203 <br />Phone: (303) 866-3567 <br />FAX: (303) 832-8106 <br />COLORADO <br />DIVISION OF <br />RECLAMATION <br />MINING <br />- $c- <br />SAFETY <br />C/r~~ Bill Owens <br />RELERF/~® Governor <br />September 25, 2006 ~ Russell eeorge <br />SEP 2 7 2006 Executive Director <br />_ Ronald W. Cattany <br />Glen WllhamS / Division of r,~damation, Division Director <br />Cotter Corporation/ Mining and Satety Natural Resource Trustee <br />P.O. BOX 700 <br />Nucla, Colorado 81424 / / <br />/ `/~ v <br />Re: JD-6 Mt~M--1977-310, Lysimeter Installation and Monitoring Plan Review and Approval. <br />Dear Mr. Williams: <br />The Division of Reclamation, Mining and Safety has reviewed the plan Cotter submitted for installation <br />of a Lysimeter well at the JD-6 Mine down gradient from existing waste dumps. The purpose of the well <br />is to collect data for review on the possible migration ofgeo-chemical constituents identified in waste <br />rock into the underlying bedrock. <br />Primarily the well will determine if there is any localized groundwater directly below and down gradient <br />from the dump that would create a path for the identified constituents to reach waters that could <br />potential create a condition that is harmful to human health and the environment. The well and <br />monitoring may provide empirical data to support modeling presented in Cotter's appeal of DMO status <br />determination by the Division. The secondary use of the well will be an early detection system for any <br />potential migration of the identified geo-chemical constituents in the future. <br />The placement of the well is in a location that Division staff and Cotter agreed upon during the May <br />2006 field visit. The construction diagrams for the well were presented with maps in a "Supplemental <br />Geology Report" submitted to the Division on August 10`h, 2006. The Division is approvin, the <br />location and construction of the well as submitted. The Division will require a copy of the drill logs and <br />construction notes within 10 working days of final construction of the well. <br />Cotter has proposed a monitoring schedule of monthly sampling to establish a baseline set of data. The <br />Division feels that a more aaoressive monitoring plan for the first 3 months is in order and gradual <br />scaling back of frequency if no detections are observed. The preferred schedule is once every 2 weeks <br />for the first 3 months provided no moisture is detected. If moisture is detected, the Division must be <br />notified within I Oworking days in writing and the sampling frequency maybe modified depending on <br />volumes and other parameters. Any water samples collected from the Lysimeter are to be tested for <br />constituents per grotndwater standards. Once the 3 month period has been completed, a review of data <br />will be used to determine future sampling intervals. If no moisture is detected during the first sampling <br />interval, the schedule may be reduced to quarterly for the next 4 quarters and possibly further after that <br />review. All sampling reports are to be submitted to the Division in writing within IO working days of <br />either the achtal sampling date or receipt of laboratory results from that sampling period. <br />STATE OF COLORADO <br />~i5 ~~,5 ~/~,gP/GlC o <br />., ~_ <br />Office of Office of <br />Mined Land Reclamation Active and Inactive Mines <br />